Air conditioning and refrigeration drain lines are typically installed in a manner that may permit drain water to stand in the line for extended periods of time. When the drain water is not continuously circulated and is instead allowed to stand in the drain pipe, algae and mold can grow and/or insects or other pests (frogs, lizards, wasps, etc.) can enter and clog the drain line. This clog may cause the drain system to back up and overflow, causing potentially serious damage to the building area where the air handler or refrigeration unit is located. This water backup can also cause the system to shut down or cause serious equipment damage.
U.S. Pat. No. 5,514,344 to D'Agaro discloses a solution dispenser for air conditioning microorganism control. Microorganism growth within water chambers of air conditioning systems is controlled by the periodic introduction of minute quantities of biocidal materials. A large volume reservoir holds a concentrated solution of biocidal material. A pump, fed from the reservoir, pumps the solution through a tube to the water chamber. The pump is actuated for very short duration periods so that only a very small volume of the solution is dispensed. The time interval between periods is very long so that the biocide concentration in the water chamber is renewed as required. The duration of the pumping periods and the time interval between periods are adjustable by controls in a timer. A normally closed check valve in the line keeps the line full between periods. An anti-siphon mechanism is provided in the line when it branches. An alarm mechanism is optionally provided to warn when the reservoir solution is depleted.
U.S. Pat. No. 5,722,458 to Potter describes a valve assembly which is placed in an air conditioner drain line for cleaning and maintenance of the drain line. The valve may be positioned to permit water or condensate to run through the drain line to a sewage drain. When the line needs to be serviced, usually due to clogging, the valve plug can be rotated to seal off the drain line upstream or downstream of the valve assembly. A slight pressure or vacuum may then be introduced at the top of the valve to force clogs loose. The valve also has a receptacle at the bottom so that an anti-fungus pellet may be dropped in which inhibits the fungus growth.
U.S. Pat. No. 5,975,113 to Haining, et al. teaches a dispenser for tableted chemical treatment material into an air conditioner condensate pan drain line and comprises a container for the tablets and a removable cover sealed to the container by a gasket. The cover includes legs that extend into the container to prevent the tableted material from floating upward and blocking the inlet and outlet to the container. The container is secured in the drain line by conduits on either end.
U.S. Pat. No. 6,487,867 to Herren discloses an automated apparatus for periodically transferring a pre-selected volume of treatment liquid to a collection pan in order to treat and prevent the clogging of the collection pan. The system includes a treatment liquid reservoir, at least one fluidic coupling, and a structure for enabling the periodic transfer of the volume of treatment liquid from the treatment liquid reservoir to the collection pan by way of the fluidic couplings, causing a treating of the collection pan.
U.S. Pat. No. 6,651,690 to Coogle describes a system for releasing growth inhibiting chemicals downstream in an air conditioner drain assembly. The system also allows a user to vary the concentration and time for releasing the growth inhibitor chemical. A main elongated tubular member is perpendicularly connected with inlet and outlet tubular members that include rotatably mounted female connectors that are removably connected with threaded male connectors. The latter in turn are connected to upstream and downstream drain pipe lines.
U.S. Pat. No. 6,892,907 to Varney teaches a device for holding and dispensing a fluid for decontaminating a condensate drip pan of an air conditioner and includes: a vessel at one end of the device for holding the fluid; and at least one fluid line having a first end inserted in a lower end of the vessel, and an opposite, lower, second end inserted in the drip or drain pan; a flow control device on the fluid line for controlling a rate of fluid drip from the fluid line into the drip or drain pan; and a drip chamber in the fluid line.
U.S. Pat. No. 7,392,658 to Hardy, III discloses a cleaning system for an air conditioner which injects a biocide followed at regular intervals, which may be followed by a rinsing flush.
U.S. Pat. No. 7,392,821 to Nakata, et al. describes a drain water discharge structure for an air conditioning apparatus in which at least any one of an internal drain pipe and an external drain pipe is formed from an antibacterial metal pipe, thereby to inhibit the generation of slime in the external drain pipe and to make the external drain pipe less apt to deterioration.
U.S. Pat. No. 7,686,034 to Coogle teaches an apparatus which applies chemicals to condensate water from an air conditioning condensate tray. It has an elongate body and a central cavity enclosed by an encircling wall. The central cavity receives chemicals to prevent the growth of microorganisms. A first tubular member is operatively connected at a first end to an aperture in the wall, and a second end extending outwardly for receiving condensate water from the condensate tray. A second tubular member is operatively connected to a second aperture in the wall opposite the first aperture aligned with the first member so that a cleaning brush may be passed through both members and into the condensate tray. Below the two tubular members a fluid outlet is provided with a connector for joining to a drainage system for draining the chemically treated condensate water from the cavity.
United States Patent Application 20060096307 by Coogle discloses a chemical delivery system for inhibiting growth in condensate drainage pipe of an air conditioner and includes a reservoir body having an open upper end, an opposing open lower end and a central cavity; an inlet tubular connector mounted perpendicularly to the reservoir body adjacent to the open upper end of reservoir body; an outlet tubular connector mounted perpendicularly to the reservoir body between the inlet tubular connector and the lower end of the reservoir body; a liquid level sensor disposed within the outlet tubular connector; a tubular cleaning spout having one end mounted perpendicularly to the reservoir body opposing the inlet tubular connector, an opposing spout opening, and a removable spout cap; a removable top cap; and a bottom cap removably connected to the open lower end of the reservoir body; thereby closing the central cavity for receiving a grown inhibiting chemical.
United States Patent Application 20070119503 by Scaringe describes a method and apparatus to prevent clogging of condensate drain lines with a biocide delivery system that prevents the growth of bioorganic growth in the liquid trap using time release biocide tablets or liquid biocide. When using solid biocide tablets erosion and dissolution of the tablets is reduced. When using liquid biocides, combination of initial release followed by gradual release of residual liquid biocide in the drain water is attainable. Drain line are promoted from clogging while being installed anywhere on the drain line upstream of the liquid trap. The apparatus can also be incorporated with a liquid trap, allowing placement anywhere in the drain line.
The foregoing patents and applications reflect the current state of the art of which the present inventor is aware. Reference to, and discussion of, these patents and applications is intended to aid in discharging Applicant's acknowledged duty of candor in disclosing information that may be relevant to the examination of claims to the present invention. However, it is respectfully submitted that none of the above-indicated patents or applications disclose, teach, suggest, show, or otherwise render obvious, either singly or when considered in combination, the invention described and claimed herein.